Applicant is aware of many commercially available concrete blocks for the construction of retaining walls and the like. In reviewing the commercially available art he has not found any block which incorporates the advantages and interlocking abilities as contained herein.
Applicant has also searched the applicable patented art and has found the following listed U.S. Patents: Heinzmann, No. 4,229,123; Schmitt, No. 2,313,363; Clarke, No. 4,081,969; Fisher, No. 3,282,056; Upson, No. 982,697; and Perada, No. 4,426,176.
Of this prior patented art it would appear that only the Heinzmann and Schmitt patents include the concept of a seating and interlock area for the joinder and connection of vertically adjacent rows or tiers of blocks.
The Schmitt patent utilizes the interlocking edge on the rear downwardly depending corner of the blocks such that an upper block will have a downwardly depending side to abut against the top of a lower tier of blocks. This structure then provides a frontal surface which is entirely flat and which may be, as illustrated in Schmitt, decorated in various forms to similate brick or stone structures.
The Heinzmann patent illustrates a block to provide a support surface and a front locking surface for the next vertically adjacent row of blocks. The unit also provides for inversion of rows of blocks wherein this capturing lip or notch may be positioned in downwardly extending location over the rear of a lower tier of blocks. The Heinzmann patent does not consider frontal decorative situations and only provides a flat front surface which, when a wall is erected provides a series of straight, stepped elements. Heinzmann embraces the concept of "loose tiers" and strongly suggests horizontal spacing between tiers to allow for plant growth. Heinzmann does not allow for either vertical or horizontal tie-in and does not consider drainage from behind the wall and into the wall. Obviously, suitable material to sustain plant growth must be provided within the openings provided by the horizontal spacing of the blocks. This is a secondary operation. The final objective of the Heinzmann patent is to provide a "living wall" in direct controversy to the concept of the applicant's device.
None of these patents provide a decorative effect as obtained through the tapered, decoratable forward surface provided by applicant and none of these patents consider the utilization of tie bar accommodations such that the constructed wall may be tied both vertically and into the earth to be retained. In addition, none of these patents are concerned with the alleviation of water that may accumulate interiorly of the blocks.
It is therefore an object of the applicant's invention to provide a concrete retaining block unit for retaining walls which provides an interlock between vertically adjacent tiers of the blocks in constructing the wall.
It is a further object of the applicant's invention to provide a concrete block for the construction of retaining walls and the like which includes a frontal surface having an inwardly and upwardly directed portion at the upper edge of the frontal surface to provide a decorative frontal arc and having a flat receiving surface therebehind to receive the next vertically adjacent block thereon and interlock the same to provide a rearwardly directed and inclined frontal surface for the constructed wall.
It is a further object of the applicant's invention to provide an interlocking concrete block structure having weight reducing apertures arranged vertically therethrough which will also permit the passage of vertical tie bars between blocks and having a rear aperture therethrough designed for drainage of water from the interior of the blocks and also provide for a dual operation of tie bar installation wherein a tie bar may be inserted into the soil behind the wall and connect the wall thereto and further providing for interconnection of both tie bars.
It is a further object of the applicant's invention to provide a concrete block as the basis for a retaining wall system which includes a block specific to corner installation.
It is a further object of the applicant's invention to provide a method for manufacture of retaining wall blocks which includes molding of two blocks in face-to-face relation and splitting the blocks to provide a decorative surface to a front surface of the block.